Diamond chair



FIG. 1 is a perspective view of a diamond chair showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side elevation thereof, the right side being a mirror image thereof; and,

FIG. 5 is a top plan view thereof. 

The ornamental design for a diamond chair, as shown and described. 